This makes for very interesting "learnings" as we used to say at AD Little.

One could certainly say that most of your chemicals stores that are flammable are also probably explosive (under the right conditions).  Let me assure you that most all powders that are metallic or contain organics are potentially combustible dusts.  The issue is not whether or not the dusts are combustible-the issue is how are they generated or used.  Gunpowder if open to the air makes for a nice exciting flame but is not explosive unless contained.

As pointed out in another response, the question is "what is the likelihood of the powder being confined and provided with a minimum ignition energy at the minimum explosive concentration?"  In the lab, this seems unlikely except for some very specialized situations such as a drying tower, etc.  I can't imagine a chemical stores situation where this would be a problem (although maybe there are some weird situations where other factors are at play).

Combustible dusts do NOT explode with ignition.  They explode with ignition and confinement.  They explode when there is a confined dust cloud.  I suggest you hire someone (CIH, CSP or Process Safety Engineer) with the experience and credentials to have a discussion with your facilities personnel and the local building code personnel.

Good luck.

Zack

S.Z. Mansdorf, PhD, CIH, CSP, QEP

Consultant in EHS and Sustainability

7184 Via Palomar

Boca Raton, FL  33433

561-212-7288

I have one interesting situation that we have recently experienced with laboratory chemicals (powdered aluminum, sulfur, and magnesium) being identified as combustible dusts. The building code designated for the space categorized as a non-H building. The building code states that in non-H spaces combustible dusts cannot be stored or used beyond quantities where an explosion risk exists if exposed to an ignition source. Interesting, the plans examiners are reviewing detailed chemical inventories by building code definitions and quantities.

We are currently working through the combustible dust situation and would also appreciate any insight to how others have documented a Hazardous Materials Management Plan for these situations or if others had to completely remove any type of combustible dust chemicals storage and use from these non-H spaces.

Marjorie